body{
    background:#ddd;
}
.box{
    background:#fff;
    height: 200px;
    padding:20px 30px;
    width:400px;
    margin: 0 auto;
    text-align:center;
}
.btn{
    width:180px;
    height:40px;
    background:#3388ff;
    border:1px solid #fff;
    color:#fff;
    font-size:14px;
}
.ipt{
    width:260px;
    padding:4px 2px;
}
.tips{
    width:440px;
    height:30px;
    margin:5px auto;
    background:#fff;
    color:red;
    border:1px solid #ccc;
    display:none;
    line-height:30px;
    padding-left:20px;
    font-size:13px;
}